January 01, 2008 by Kathleen M. Wong
Ask most people to name the most important species of our grassland habitats, and they'll probably pick coyotes, golden eagles, or even rattlesnakes. But experts say that the strongest contender of all is the animal eaten by all those other ones: the lowly California ground squirrel, a true keystone of local grasslands. Belowground, the squirrels' lengthy burrows harbor insects, snakes, owls, and even frogs and salamanders that couldn't live in such a dry landscape without the squirrels' help. And above-ground, they've evolved some unusual defenses that allow them to thrive, even as they feed so many others.